This invention relates to photo processing machines, and in particular to apparatus for automating the recycling of developer in such machines.
To date, it has been difficult and expensive to reuse and recycle developer. There are those who believe that it is merely necessary to cut back the replenisher rate for each film. For instance, if the normal rate is 100 cc, the recycling could be accomplished by reducing it to 50 cc. The problem with that approach, however, is that it does not account for the buildup of certain salts that can act to inhibit the development process. The only way to avoid such a buildup is to redilute the used developer with new developer.
The only method for doing so to date has been practiced only in large photo finishing plants and large hospitals, both of which have central mixing facilities. In those cases an operator could isolate several hundred gallons of used developer and reintroduce that developer into several hundred more gallons of new developer. This process is expensive even for such large companies because of the labor-intensive nature of the work, and is simply unavailable for smaller companies.
This invention relates to improvements to the methods and apparatus described above and to solutions to the problems raised or not solved thereby.